Join Date: Feb 2006
Location: Colorado Springs
Yes, you're absolutely correct that there aren't any really wide tires that are an exaxt fit, so I've been working from what's available from Hoosier, BFG, etc. The bigger problem, as you know, is wheel sizes.
I've found several, lower cost wheels from tirerack that are 17" x 8", pricing from ~$140-$250, wheels weighing ~21-23 lbs, and the Rial Nogoro, for $170 each, @22 lbs, states that it has a 5 mm offset (with a 5.78" backspacing). The offset/backspacing is the best I've seen. This isn't great, but it's a lot better than the 35-42 mm offset (5.9"-6.2" backspacing) on most of the wheels -- and the 255/40 x 17 BFG R1s specify a wheel width range of 8.5-10.0 inches. Which would mean that the wheel would be within 0.5" of the minimin recommended width spec. Remember, I'm only concerned with wheels and tires to race with. I run 7" rims with 215/45 street tires. And I have a set of 7.5" rims for Hoosier Wets. I've seen the BFGs in 255, a guy with a trailered STI runs them, and they are visibly as wide (perhaps wider on the ground) than the Hoosier 275s).
I'm also not terribly concerned with the tire diameter so long as it's not more than about an inch larger -- the larger diameter reduces the effective torque and I already have issues spinning the front tires under power coming out of tighter corners (and National Tour sites usually have higher-speed courses). When I ran down in San Diego this year with 225/40s, I hit the rev-limiter three times on each run -- had I been geared a bit higher (a larger tire), I could have been faster, with less tire spin, again, faster).
Autocross isn't so much absolute speed or cornering as it is maintaining the 'quickest' run -- you can be slower, but win.